On 12/11/20 12:39 PM, Vladimir Sementsov-Ogievskiy wrote: > We are generally moving to int64_t for both offset and bytes parameters > on all io paths. > > Main motivation is realization of 64-bit write_zeroes operation for > fast zeroing large disk chunks, up to the whole disk. > > We chose signed type, to be consistent with off_t (which is signed) and > with possibility for signed return type (where negative value means > error). > > So, prepare bdrv_aligned_preadv() now. > > Make byte variable in bdrv_padding_rmw_read() int64_t, as it defined > only to be passed to bdrv_aligned_preadv().
Reads awkwardly, how about: Make the byte variable in bdrv_padding_rmw_read() int64_t, as it is only used for pass-through to bdrv_aligned_preadv(). > > All bdrv_aligned_preadv() callers are safe as type is widening. Let's > look inside: > > - add a new-style assertion that request is good. > - callees bdrv_is_allocated(), bdrv_co_do_copy_on_readv() supports > int64_t bytes > - conversion of bytes_remaining is OK, as we never has requests have > overflowing BDRV_MAX_LENGTH > - looping through bytes_remaining is ok, num is updated to int64_t > - for bdrv_driver_preadv we have same limit of max_transfer > - qemu_iovec_memset is OK, as bytes+qiov_offset should not overflow > qiov->size anyway (thanks to bdrv_check_qiov_request()) > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > --- > block/io.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > Reviewed-by: Eric Blake <ebl...@redhat.com> -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org